The extended shutdown order affects more than 1.7 million students in public and private K-12 schools. It means children will spend the rest of the year learning remotely.
The order applies through the last day of the current academic year, a date that varies among districts because calendars are set by school boards.
Gov. Tom Wolf made the decision after consulting with Education Secretary Pedro Rivera and Dr. Rachel Levine, the state health secretary, Wolf's spokeswoman said Thursday.
"Schools will remain closed for the rest of the academic year, but that doesn't mean learning is stopping in Pennsylvania," Wolf said in a video announcing the closure. "Teaching and learning will continue. Free meals for kids will continue. Connections will continue."
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Dr. William Hite, superintendent of the School District of Philadelphia, found out about the announcement during a news conference on Thursday morning.
"That doesn't change what we intend to do with respect to remote learning, but it does answer the question of whether or not we will return to the school building. ... But it is why the remote learning plan is so critically important," Hite said.
He said the announcement now allows the district to plan more specifically.
Annette Stevenson with the Pennsylvania School Boards Association welcomed the decision.
"I think it'll bring great relief to the schools and the school leaders, because what it'll do is allow them to formulate the long-term plan instead of having this interim plan in place," Stevenson said.
Rivera told The Associated Press that decisions about how to handle graduations, which are made by local school districts, will depend on the extent of social distancing and stay-at-home direction in place as the graduation season nears.
Some districts are making plans for virtual commencement exercises, Rivera said.
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Schools might be able to provide summer programming that starts on the day after their academic years end, although re-opening buildings will depend on further action by the governor, Rivera said.
"Reopening will depend on the decision by the governor, based on the data and the research and the expectations set by the secretary of health," Rivera said.
His order also waived several other provisions of law and regulations, including one related to teacher evaluations.
Wolf first closed schools on March 13, initially for two weeks, as the virus continued its march across Pennsylvania. The Democratic governor tacked on another week before closing schools indefinitely, part of a series of progressively tougher measures meant to contain the outbreak and prevent hospitals from becoming overwhelmed.
A state law passed last month mandates that schools provide an education during the pandemic, either by teaching new material or reviewing material that was already taught.
Rivera said about half of the school districts have sent his department plans that describe how they are continuing to educate children during the shutdown.
Wolf also has closed nonessential businesses and ordered all Pennsylvania residents to stay home.
Pennsylvania has seen more than 16,000 confirmed COVID-19 infections and 310 deaths.
For most people, the virus causes mild or moderate symptoms that clear up in a couple of weeks. Older adults and people with existing health problems are at higher risk of more severe illness, including pneumonia, or death.